1H NMR fingerprint and chemometric analysis of biochemical stability in fresh cheeses enriched with corn silk, grape seed, and tangerine peel extracts.

This study applied proton nuclear magnetic resonance (1H NMR)-based metabolomic and lipidomic profiling to evaluate biochemical stability in ricotta, cottage, and curd cheeses formulated with plant-derived extracts from tangerine peel (Citrus reticulata), grape seed (Vitis vinifera L.), and corn silk (Stigma maydis). Cheeses were stored at 4 °C and 12 °C for 14 days, and polar and lipophilic extracts were analyzed. PCA indicated that cheese matrix and storage temperature were the main sources of compositional variation, whereas PLS-DA provided useful predictive discrimination only for cheese type. Corn silk and grape seed extracts were associated with greater preservation of residual carbohydrates and unsaturated lipid signals and lower accumulation of acidogenic and oxidation-related metabolites, whereas tangerine peel showed a weaker protective trend. These findings support 1H NMR fingerprinting as a useful approach for monitoring freshness-related biochemical changes in fresh cheeses and indicate that selected agro-industrial by-product extracts show potential as ingredients for clean-label preservation strategies. Further chemical characterisation of the extracts and targeted microbiological, physicochemical, sensory, and dose-response studies are required to establish their preservative efficacy and technological applicability.